One of the most scrutinized and approved oils on earth. It's arguably never the "best" but it's really, really hard to think of an application for which it would be wholly unsuitable. When everyone from Porsche to Mercedes to BMW to GM to VW can agree that an oil meets or surpasses their demanding OEM tests, that's a pretty special oil in anyone's book...
And historically, M1's 0w oils are showcase oils that always have the best of their formulation knowledge it seems.